The present disclosure is an alignment clamp for plates to be welded. In the welding of plates such as the formation of a pressure vessel, it is necessary to join adjacent plates, either planar or curved as required by welding. The plates must be carefully aligned before the welding process can begin. Good craftsmanship dictates that the alignment be almost perfect to measurably reduce problems in welding. Welding is a difficult enough art, what with problems resulting from spot heating, expansion, shrinkage on cooling, and the requirements for a perfect weld as in the case of a pressure vessel. Thus, the apparatus of the present invention is very needed.
Devices known in the prior art have attempted with some degree of sucess to align plates to be welded. They are however, rather clumsy and cumbersome to use. It is difficult to align two plates which may themselves weigh several thousand pounds through the use of an alignment device which also is large, cumbersome, and difficult for a welder to install. The present invention is a device which is relatively small so that the fitter does not have to strain mightily to position two plates and a very large alignment tool before welding begins. With this in view, the disclosed apparatus is an alignment tool which is quite small and which can be installed in multiples to align plates prior to welding. In the example of welding adjacent sections of tank sections 4 feet in diameter, a minimum of three of the alignment tools of the present invention is preferably used and as many as six or eight can be used should there be dents or distortion from a perfect circular shape of the plate to be welded. They can be installed rather quickly. The alignment tool of the present invention is easily installed at multiple locations around the plates to be welded after which the welding process can begin whereby a bead is formed between the plates and they are joined. Gaps are left in the welded bead where the alignment tool contacts the plate and which is subsequently removed. Thereafter, the gaps can be welded.